Mounting assembly for optical equipment

ABSTRACT

A mounting assembly (1) for optical equipment comprises a plurality of trays (2) detachably hinged together. Each tray (2) may be adapted to carry optical components as well as optical fibre splices and they can be hinged together into a stack in one of a number of different configurations, allowing convenient access for both installation and maintenance. The assembly (1) finds particular application in optical communications equipment.

BACKGROUND OF THE INVENTION

The present invention relates to a mounting assembly for opticalequipment. In particular it relates to a multiple tray storage systemfor use in optical communication systems.

It is known in the field of optical communications to mount opticalcomponents, such as opto-electronic components, on boards. One or twocomponents may be mounted on a board, with associated circuitry, andthere is commonly an associated fibre splice organiser tray. The spliceorganiser tray accommodates the splices between optical fibre tailsattached to individual components, and optical fibres carrying signalsto or away from those components. Each fibre splice necessarily has alength of spare fibre associated with it so that the splice can bebroken and remade as required. This spare fibre is also stored on thesplice organiser tray.

Where several splice organiser trays are required, they may convenientlybe hinged together into a stack. This gives a relatively compact storagearrangement, access to particular trays being made possible by thehinges which allow the stack to be opened like a book.

SUMMARY OF THE INVENTION

It has now been realised, in making the present invention, that it ispossible to design a mounting assembly for optical equipment which isparticularly versatile and convenient with regard to component access.

It is object of the present invention to provide a mounting assembly foroptical equipment which can provide good access to the equipment, forinstance for either installation or maintenance.

It has been found that a mounting assembly according to an embodiment ofthe present invention can also simplify the provision of optical fibretails to components, and the storage of associated fibre splices.

According to a first aspect of the present invention there is provided amounting assembly for optical equipment comprising a plurality of trayswhich can be stacked, the trays being provided with means for mountingoptical components, wherein the trays are further provided withdetachable connecting hinges such that the trays can be hingedlyconnected together in a selected one of a plurality of differentconfigurations.

By using detachable connecting hinges it is possible to increase greatlythe versatility of a mounting assembly. This has major advantages. Forinstance, if the trays each have effectively two opposing edges and canbe stacked so that the edges are aligned, by providing detachableconnecting hinges at both edges of the trays it becomes possible toselect a configuration in which a stack of trays can be opened eitherlike a book, each tray constituting a page of the "book", or, byreconfiguring the hinges, in a zig-zag fashion. This is useful atinstallation because the opening the stack zig-zag fashion it ispossible to expose a single large surface on which optical componentsand their associated fibre splices and spare fibre can be optimallyarranged. However it is also subsequently useful in maintenance becauseby reconfiguring the hinges the stack can then be opened like a book toexpose any selected component with minimal disturbance to the rest ofthe stack.

Preferably, instead of there being a splice organiser tray on which aplurality of optical fibre splices are arranged, each component havingan associated fibre splice is mounted on a tray with that splice.

According to a second aspect of the present invention there is provideda tray for use in a mounting assembly according to the first aspect ofthe present invention, which tray is provided with means for mounting atleast one optical component and for mounting a fibre splice associatedwith that component.

This has obvious advantages for maintenance purposes in an assemblyaccording to the present invention since where it becomes possible toopen a stack of trays selectively at a particular component, it isclearly advantageous that an associated fibre splice is also immediatelyaccessible so that the component can be conveniently replaced ifnecessary. It also has the advantage that because the component andsplice are on a common tray, there is no need to provide a ruggedisedfibre tail from the component to the splice. This has been necessary inthe past to protect the fibre tail where it is being taken between twoseparate and relatively movable storage arrangements, these being acomponent board and a splice organiser tray.

BRIEF DESCRIPTION OF THE DRAWINGS

A mounting assembly for optical equipment will now be described, by wayof example only, with reference to the accompanying Figures in which:

FIGS. 1a and 1b show the mounting assembly, schematically, in each oftwo different hinge configurations;

FIG. 2 shows a plan view of a tray for use in the mounting assembly ofFIG. 1;

FIG. 3 shows an end elevation of the tray of FIG. 2;

FIG. 4 shows a cross section taken along the line A--A of FIG. 3, viewedin the direction indicated by the arrows;

FIG. 5 shows a plan view of an alternative tray to that of FIG. 2;

FIG. 6 shows a side elevation of the tray of FIG. 5;

FIG. 7 shows a cross section of the tray of FIG. 5 taken along the lineC--C and viewed in the direction indicated by the arrows;

FIG. 8 shows a cross section of the tray of FIG. 5 taken along the lineB--B and viewed in the direction indicated by the arrows; and

FIG. 9 shows a plan view of another alternative tray to that of FIG. 2.

It should be noted that where a cross section is shown in the Figures,instead of being hatched the cross section portions are shown as a solidarea.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Referring to FIGS. 1a and 1b, the mounting assembly 1 comprises aplurality of trays 2 with demountable hinges 3 at their corners. Thetrays 2 are stacked together, adjacent trays 2 being attached to eachother by means of the hinges 3. At each end of the assembly 1, a cover21 is provided.

Two alternative configurations are shown, in FIGS. 1a and 1brespectively. In a first configuration, shown in FIG. 1a, each of thetrays 2 is hinged to each adjacent tray 2 at the same edge 4 withrespect to the stack. The opposing edge 5 of each tray 2 is unattached.Hence the stack can be opened like a book, between any pair of adjacenttrays, each tray 2 consituting a page of the "book". This gives accessto either face 6 of all the trays 2 in the assembly 1.

In a second configuration, shown in FIG. 1b, each of the trays 2 ishinged to its adjacent trays at alternate edges 4, 5 with respect to thestack. Hence the stack can be opened zig-zag fashion to expose apreselected surface area. That area may range from being as small as thearea of the faces 6 of two adjacent trays 2, to being as large as thetotal area of one side of all the trays 2, put together, if theasssembly 1 is fully opened out.

By using demountable hinges 3, it is possible to go from oneconfiguration to the other, and indeed to any further configurationrequired, which might be a combination of the first and second. This canbe achieved simply by disconnecting certain hinges 3 and connecting adifferent combination.

The trays 2 and the hinges 3 will now be described in more detail, withreference to FIGS. 2, 3 and 4.

Referring to FIG. 2, each tray 2 comprises substantially a mouldedplastic plate provided with optical fibre guides 8 and with mountingpoints for components 9. Optical fibre 10 can be brought onto the tray 2at either long side, the tray 2 being roughly rectangular with roundedcorners. The fibre 10 is guided and retained on the tray 2 by means offibre guides 8, spare fibre being stored around the edge of the tray 2.

At each corner of the tray 2 are the detachable connecting hinges 3.Referring to FIG. 3, each hinge 3 comprises two complementary parts 3a,3b, mounted on respective trays 2 so that when the trays 2 are stackedtogether, a hinge part 3a on one tray 2 can be connected with acomplementary hinge part 3b on the adjacent tray 2 to complete adetachable connecting hinge 3. The hinge parts 3a, 3b comprises a collar3a and a peg 3b respectively, the peg 3b fitting into the collar 3a tocomplete a hinge 3. The collar 3a in each case is mounted on a slightlyresilient neck 3c, this allowing the hinge 3 to be either made orunmade.

Referring to FIGS. 2 and 4, the tray 2 is provided with mounting points9 for components (not shown) of different types. The centre 12 of thetray is hollow and can accommodate a component whose depth is of thesame order as that of the tray 2, without the component protruding fromthe tray 2. Towards the edge of the tray 2 are provided further mountingpoints 9 which can accommodate shallower components, on either face.Other mounting points may also be provided.

It would be possible to accommodate particularly large components byusing adjacent trays 2 in an assembly with complementary cut-outsections, or depressions, which co-operate to provide a suitable cavity.

The dimensions of each tray 2 ar 10×21×1 cm. This allows the opticalfibre to be guided round curves of minimum bend radius 3.5 cm. The fibreenters and leaves the tray 2 at a long side 22 of the tray 2.

Referring to FIG. 5, a tray 2 may have a number of alternative features.

When two adjacent trays 2 are hinged together, clearly any fibre goingfrom one tray 2 to the other must do so at the long side between thehinges 3. To avoid overbending the fibre during manipulation of a trayassembly, the fibre is guided so that it enters or leaves a tray 2following a line which is substantially along the hinge axis. It isconvenient to provide cutouts 13 at the point where a fibre enters orleaves a tray 2. This allows a fibre to go easily from one face to theother of a particular tray 2, or to be led onto either face of a tray 2,from elswhere. To improve guidance of the fibre, as well as fibre guides8, channels 23 may be provided particularly at the long sides 22 of atray 2.

The trays 2 may be provided with a multiplicity of holes 14 of differentsizes. The smallest of these 14a are equivalent to the conventionalholes provided on a printed circuit board. This allows standard mountingtechniques for electrical components to be applied. The other holes 14may be used for instance to mount components, or to insert detachableoptical fibre guides 8a so that the configuration of optical fibres onthe tray can be changed in a flexible manner.

Referring to FIGS. 6 and 7, the general principle of the fibre guides 8and component mounting points 9 is that they comprise pairs of tabslying beside one another, each mounted in the plane of an oppositerespective face of the tray 2. This is convenient in design, providingin each case a tray with the same mounting and guiding facilities oneach face.

Referring to FIGS. 7 and 8, it is possible to see that the centre 12 ofthe tray 2 of FIG. 5 is again an aperture, allowing accommodation ofparticularly large components if necessary.

Referring to FIG. 9, in which only a portion of the optical fibre 10which might be stored on the tray 2 is shown, a tray 2 can be used toprovide multiple mounting points for optical fibre splices 26 if thisshould be convenient. Such an arrangement may be particularly convenientif the tray 2 is to be used for mounting a plurality of optical fibrecouplers 27 (shown only schematically) with all their associated fibresplices 26. A tray 2 having a hollow centre 12 may be converted formounting fibre splices 26 in the centre 12 by installing a central card28 on which the splices 26 can be mounted. Further splices 29 may alsobe mounted elsewhere on the tray 2, using a dedicated splice chip 30 tohold them in place.

If it is convenient, a cover (not shown) might be provided for one orother face of a tray 2. This might be convenient where a tray 2 is to besupplied to a user with components such as couplers already mounted onone face. Fibre tails from the couplers could be brought through thetray 2 to splices mounted on the opposite face of the tray 2, where theycould be accessed for installation purposes by the user. The componentsor couplers however could be protected, for instance from mechanicaldamage, by a cover since it may be unlikely that the user will requireto access the components themselves.

The versatility of mounting assemblies according to embodiments of thepresent invention is particularly useful in first installing opticalequipment and fibre onto the trays of an assembly 1, then later inperforming maintenance tasks. The equipment and fibre can be installedonto the trays 2 when they are in a zig-zag configuration as shown inFIG. 1b, large surface areas then being exposable. This allows layoutsto be designed and carried out in a convenient manner. Subsequently itmay become important to be able to access particular components forrepair, maintenance or redesign. It may then be more convenient that theassembly can be opened book fashion to expose a face of a particulartray 2. This can be simply done by merely reconfiguring the hinges 3,disconnecting all those on one side of the assembly 1 and connectingthose hitherto unconnected on the other side of the assembly 1,achieving a configuration as shown in FIG. 1a.

It may be desirable, once components and fibre have been installed, toreconfigure the hinges 3 and then to make them permanent in thereconfigured arrangement. This can make the assembly 1 more robust inuse. For instance, by heating the end of the peg 3b of each hinge 3, athickening can be created which prevents its extraction from theassociated collar 3a. Alternatively, a nut or cap could be mounted onthe end of the peg 3b.

An advantage of making hinges permanent in a reconfigured arrangement isthat this can be used to prevent damage to optical fibres which areguided to lie across a hinged joint, for instance between trays.

It will be realised that electrical conductors may also be mounted ontrays of an assembly. This allows electrical connections to be made forinstance to supply power to opto-electronic components. The electricalconductors may be guided in the same manner as optical fibres, both inaccessing a tray and in being mounted on a face of a tray.

What is claimed is:
 1. A mounting assembly for optical equipment,comprising a plurality of trays which can be stacked, the trays beingprovided with means for mounting optical components, wherein the traysare further provided with demountable connecting hinges such that thetrays can be hingedly connected together in a selected one of aplurality of different configurations.
 2. A mounting assembly accordingto claim 1, wherein the trays are stacked, a first of the plurality ofconfigurations allowing the trays to be accessed by opening them outzig-zag fashion and a second of the plurality of configurations allowingeach face of at least one of the trays to be accessed by opening thestack of trays book fashion.
 3. A mounting assembly according to claim1, wherein each of the hinges comprises co-operating parts, first andsecond of the co-operating parts being mounted on different respectivetrays in the assembly.
 4. A mounting assembly according to claim 3,wherein the first co-operating part of a hinge comprises a peg and thesecond co-operating part of that hinge comprises a collar.
 5. A mountingassembly according to claim 4, wherein one of the co-operating parts ismounted on a resilient neck.
 6. A mounting assembly according to claim1, wherein at least one of the trays is provided with means for mountingboth an optical or an opto-electronic component, and an optical fibresplice with associated spare fibre.
 7. A tray for use in a mountingassembly according to claim 1, wherein the tray is provided with meansfor mounting at least one optical component and with means for mountingan optical fibre splice associated with that component.
 8. An opticalcircuit mounting tray for use in an assembly of plural parallel suchtrays, said tray comprising:a generally planar configuration including afirst hinge structure which is connectable to a mating second hingestructure on another generally parallel tray, said tray being hingedlymovable about a hinge axis substantially parallel to the tray plane whenthe first and second hinge structures are interconnected.
 9. An opticalcircuit mounting tray as in claim 8 wherein said tray has eight corners,four of said corners having said first hinge structure and four of saidcorners having said second hinge structure which is different than saidfirst hinge structure.
 10. An optical circuit mounting tray as in claim8 wherein said tray includes a pair of side openings respectivelyaligned with a pair of hinge axes, one at each opposite side of thetray.
 11. An optical circuit mounting tray as in claim 8 which can beselectively connected to another similar tray for hinged motion abouteither of said pair of hinge axes.
 12. An optical circuit mounting trayas in claim 8 wherein said tray includes predefined areas foraccommodating optical devices and interconnected optical fibre.
 13. Anoptical circuit mounting tray as in claim 8 wherein at least one of saidfirst and second hinge structures is selectively deformable so as tomake permanent a given hinged connection with another tray.